A guest blog from Lynne Hillenbrand, Caltech’s executive officer of astronomy The Cahill Center for Astronomy and Astrophysics on the campus of the California Institute of Technology, in Pasadena, California, is home to many of the world's pioneers in astronomical discovery, experiment, and theory. Our new building, opened in January, was designed to incorporate groups from across the campus into a single space and to foster their interactions...

Perplexed by planets? Confused by cosmology? Baffled by black holes? Then send in your questions to Astronomy magazine at askastro@astronomy.com . If you have an astronomy question about observing, the planets, stars, cosmology, or astronomy history, send it in! Five are selected each month for publication in the Ask Astro section of Astronomy magazine. If your question is selected, we will forward it to an expert for his or her response. Then, the...

Tuesday at the European Week of Astronomy and Space Science meeting in Hatfield, England, astronomers announced a new milestone: an extrasolar planet with the lowest confirmed mass of any yet discovered around a normal star . “Confirmed” . . . “normal star” . . . seems like a lot of caveats, doesn’t it? Let me explain. The planet is called Gliese 581 e, and the research says it contains 1.9 times Earth’s mass. Earth-mass planets are the holy grails...

The discovery and optical imaging of Fomalhaut b , a planet orbiting the nearby star Fomalhaut, has wider implications for exoplanet science. I talked to NASA scientist Marc Kuchner about it. Kuchner works in the Exoplanets and Stellar Astrophysics Laboratory at Goddard Space Flight Center in Greenbelt, Maryland. He uses computer models to study the effect planets have on interplanetary dust. Kuchner (pictured at left below) and Christopher Stark...

They've discovered Earth ... again. The astronomy blogosphere is abuzz with news of "shrunken versions of our solar system" and "miniature worlds in the making," at least according to the press releases I've been reading. Nobody has called them " Hobbit solar systems" yet, but give them time. Alexander Scholz of the University of St. Andrews in Scotland , and Ray Jayawardhana from the University of Toronto reported...